Recognized by the 2019 Nobel Prize in Chemistry, rechargeable lithium-ion battery (LIB) has become a world-revolutionary technology. Further developments of LIB-based and “beyond LIBs” regarding capacity, cycle life, and safety are intimately associated with the fundamental understanding of chemical compositions, structures, physical properties of electrodes and electrolytes, and other related components. The time-evolving snapshots of the dynamical processes occurring during the battery operation can help design better strategies to prevent the formation of uncontrolled interphase layers, dendrites, electrode/electrolyte decompositions, and generation of gases. Photoemission spectroscopy (PES) has become one of the important techniques for understanding the aforementioned aspects. However, many potential pitfalls and cautions need to be considered from sample preparation, during PES measurements, to data analyses. Although the primary focus of this article is not to evaluate the PES technique itself, we first introduce a minimal set of fundamental concepts to minimize misinterpretation arising from the physics of PES. Subsequently, we examine studies that utilize PES techniques to determine chemical compositions of solid- and liquid-state battery materials, energy level diagrams that bridge different terminologies between PES and electrochemistry, along with the theoretical aspects of PES evolving from first-principle calculations to machine learning. Toward the end of this review, we outline potential future research directions.

中文翻译：

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电池材料的光电子能谱


可充电锂离子电池 （LIB） 获得 2019 年诺贝尔化学奖，已成为一项世界革命性的技术。基于 LIB 和“超越 LIB”的容量、循环寿命和安全性的进一步发展与对化学成分、结构、电极和电解质以及其他相关组件的物理性质的基本理解密切相关。电池运行过程中发生的动态过程的时间演变快照有助于设计更好的策略，以防止形成不受控制的相层、枝晶、电极/电解质分解和气体的产生。光电子能谱 （PES） 已成为理解上述方面的重要技术之一。然而，从样品制备、PES 测量期间到数据分析，需要考虑许多潜在的陷阱和注意事项。虽然本文的主要重点不是评估 PES 技术本身，但我们首先介绍了一组最少的基本概念，以尽量减少 PES 物理学引起的误解。随后，我们研究了利用 PES 技术确定固态和液态电池材料的化学成分的研究、桥接 PES 和电化学之间不同术语的能级图，以及 PES 从第一性原理计算演变到机器学习的理论方面。在这篇综述的最后，我们概述了未来潜在的研究方向。